Best algorithm for matching colours.

Question

I have an array of around 200 colours in RGB format. I want to write a program that takes any RGB colour and tries to match a colour from the array that is most \"similar\".

Answer 1

Convert all of the colors to the CIE Lab color space and compute the distance in that space

deltaE = sqrt(deltaL^2 + deltaA^2 + deltaB^2)

Colors with the lowest deltaE are the most perceptually similar to each other.